Optical communications may soon be the standard for high-speed local area networks (LAN). Within a few years, the data rates on such networks will be about one gigabit per second (Gbit/s). As capacity requirements exceed 1 Gbit/s, it may be desirable to use wavelength division multiplexing to increase the aggregate data rate of existing fiber in such LANs.
A multiple vertical cavity surface emitting laser (VCSEL) transmitter operating at 820, 835, 850 and 865 nm has recently been proposed as a WDM source for a LAN. To demultiplex the signal, a complicated arrangement of filters packaged with waveguide splitters was used. See, Aronson et al., "Low-Cost Multimode WDM for Local Area Networks," Postdeadline Session of the 1997 Optical Fiber Communication Conference.
It would be desirable, therefore, to have a simpler arrangement for demultiplexing such a signal to minimize the cost of such a network.